Vehicle product line with multiple gear train assemblies

ABSTRACT

A line of vehicle transmissions is provided. The vehicle line includes a first multi-stage gear train assembly with at least two stages, a second multi-stage gear train assembly with at least three stages, and a housing including a first section removably attached to a second section. The second housing section is configured to receive the first and second multi-stage gear train assemblies in different product arrangements.

TECHNICAL FIELD

The present disclosure relates to a vehicle powertrain line with aplurality of gear train assemblies.

BACKGROUND AND SUMMARY

In vehicle design processes, production cost is an ever-present factor.Certain vehicle powertrain platforms may have varied gear ratio targetsthat serve different end-use performance objectives. Thus, to meet thedifferent gear ratio design goals, the ratio of the gearbox stages maybe varied. However, in previous drivetrains, the housing may beredesigned to accommodate for the different gearbox layouts. The housingredesign process, may increase manufacturing complexity and, in somecases, production costs.

U.S. Pat. No. 9,789,754 B2 to Zhu et al. teaches a dual-motor vehiclesystem that utilizes a layshaft. At the layshaft, power from the both ofthe motors is combined and transmitted to downstream drive wheels. Zhu'ssystem includes a synchronizer designed to shift between different gearratios and a neutral position.

The inventor has identified several issues with Zhu's gearbox and otherprior gearbox designs. Zhu's and other gearboxes may, for instance, besusceptible to component degradation and power delays when shiftingtranspires. Further, certain electric motors may be able to achieve acomparatively wide variance in output speed range, when compared tointernal combustion engines, for example. Pairing these electric motorswith shiftable transmission may add complexity and increase potentialgearbox degradation modes.

To overcome at least some of the aforementioned challenges a vehicleproduct line is provided. The vehicle product line includes a firstmulti-stage gear train assembly with at least two stages. The productline further includes a second multi-stage gear train assembly with atleast three stages and a different number of stages than the firstmulti-stage gear train assembly. A housing with a first sectionremovably attached to a second section is additionally included in theproduct line. In the housing, the second section is configured toreceive the first and second multi-stage gear train assemblies indifferent product arrangements. Providing a gearbox product line with acommon housing enables manufacturing efficiency gains to be achievedwhile meeting a wider variation in gear ratios. Thus, the product lineprovides a wider range of fixed gear ratios for different end-users.

In another example, the multi-stage gear train assemblies each include adifferential having an equivalent final drive ratio and the firstmulti-stage gear train assembly has an overall gear ratio that is lessthan the overall gear ratio of the second multi-stage gear trainassembly. In this way, the product line may include a common final driveassembly while varying the overall gear ratio of the different geartrains. Consequently, the product line's manufacturing complexity can befurther reduced and its end-use applicability can be further expanded.

It should be understood that the summary above is provided to introducein simplified form a selection of concepts that are further described inthe detailed description. It is not meant to identify key or essentialfeatures of the claimed subject matter, the scope of which is defineduniquely by the claims that follow the detailed description.Furthermore, the claimed subject matter is not limited toimplementations that solve any disadvantages noted above or in any partof this disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic representation of a first electric axle assemblyin a vehicle product line.

FIG. 2 is a schematic representation of a second electric axle assemblyin the product line.

FIGS. 3 and 4 are perspective and side views of an exemplaryillustration of the second electric axle assembly.

FIG. 5 is a detailed view of the gear train included in the example ofthe second electric axle assembly, depicted in FIGS. 3 and 4.

FIG. 6 is an exemplary illustration of the first electric axle assembly.

FIG. 7 is a detailed view of the gear train included in the example ofthe first electric axle assembly, depicted in FIG. 6.

FIG. 8 is a detailed view of an intermediate shaft included in the geartrain, depicted in FIG. 5.

FIG. 9 is a detailed view of an intermediate shaft included in the geartrain, depicted in FIG. 7.

FIGS. 3-9 are drawn approximately to scale. However, other relativedimensions may be used, in other embodiments.

DETAILED DESCRIPTION

A vehicle product line leveraging the use of a housing which packagesmultiple gearboxes with different ratios. The gearboxes include a variednumber of layshafts to achieve the gear reduction ratio flexibility. Theproduct line's applicability is expanded when these flexible ratiogearboxes are used while manufacturing procedures are simplified andmanufacturing costs are driven down. In one example, one of thegearboxes may include a single layshaft and another gearbox may includemultiple layshafts. In gearbox with multiple layshafts, the centerdistance between an input gear and a second layshaft may be selected toallow solely variations in the sizing of an input gear and idler gear tobe varied to enable the ratio flexibility to be achieved, if wanted.However, gearboxes in the product line with additional gear variationslie within the scope of this disclosure.

In further examples, the different gearboxes may use common bearings,parking devices, and/or have similar final drive ratios to furtherdecrease manufacturing complexity and manufacturing costs. Thus, thegearboxes may have overlapping components to harness economies of scalecost reductions. In further examples, the housing may form a portion ofan electric beam axle assembly when the gearboxes are packaged therein.This electric beam axle construction enables further expansion of thevehicle product line's applicability due to the axle's packagingefficiency, increased reliability, and increased energy efficiency incomparison to electric vehicle (EV) powertrains with the motor spacedaway from the drive axle(s).

FIGS. 1 and 2 schematically illustrate a first and a second drive axlesystem arrangement in a product line, the drive axles include geartrains which have different gear ratios designed to be packaged in acommon housing. FIGS. 3-4 illustrate detailed views of an example of thesecond electric axle arrangement with multiple intermediate shaftsproviding a relatively high gear reduction. FIG. 5 illustrates the geartrain included in the second electric axle arrangement. FIG. 6 shows anexample of the first electric axle arrangement with a relatively lowgear reduction and with one intermediate shaft packaged in a similarhousing to the gear train in the second electric axle arrangement, shownin FIGS. 3-4. FIG. 7 depicts a detailed view of a gear train included inthe second electric axle arrangement, shown in FIG. 6. FIGS. 8-9 showexemplary layshafts in the second and first electric axle arrangements.

FIG. 1 shows a schematic depiction of a vehicle 100 having a firstexample of an electric drive axle 102 that forms at least a portion of avehicle drive train. The stick diagram of FIG. 1 provides a topology ofthe vehicle, drive axle, and corresponding components. The vehicle 100may take a variety of forms, such as a light, medium, or heavy dutyvehicle. Further, the vehicle may be a battery electric vehicle (BEV)where the internal combustion engine is omitted. Alternatively, thevehicle may be a hybrid elective vehicle with an internal combustionengine providing power to a battery or motive power to another driveaxle. For instance, in one use-case hybrid vehicle configuration, theinternal combustion engine may assist in recharging an energy storagedevice 103, during certain conditions. In another use-case hybridvehicle configuration, the internal combustion engine may be configuredto provide rotational energy to a differential 104 or other suitablelocations in the gear train. In yet another use-case hybrid vehicleconfiguration, the engine may provide rotational input to another driveaxle.

The electric drive axle 102 includes an electric motor-generator 106,although motors without regenerative capabilities have beencontemplated. The electric motor-generator 106 includes a stator 108 anda rotor 110. The motor-generator 106 may be electrically coupled to theenergy storage device 103 (e.g., battery, capacitor, combinationsthereof, and the like). Arrows 112 signify the energy transfer betweenthe electric motor-generator 106 and the energy storage device 103 thatmay occur during different modes of system operation. The electricmotor-generator 106 may include conventional components for generatingrotational output (e.g., forward and reverse drive rotational output)and/or electrical energy for recharging the energy storage device 103such as a rotor electromagnetically interacting with a stator, toprovide the aforementioned energy transfer functionality.

The motor-generator 106 includes a rotor shaft 114 with a first bearing116 and a second bearing 118 coupled thereto. As described herein, abearing is a device used to allow rotation of a shaft or othercomponent. Roller bearings, ball bearings, thrust bearings, combinationsthereof, and the like may be used. The bearings 116, 118 as well as theother bearings described herein may therefore include components such asinner races, outer races, roller elements (e.g., ball bearings,cylindrical rollers, tapered cylindrical rollers, etc.). Moreover, thesize and/or configuration of at least a portion of the bearings mayvary, in some cases. However, at least a portion of the bearings mayhave similar sizes and/or constructions. Factors such as shaft loading,expected shaft speed, gear sizing, packaging constraints, etc. may betaken into account when selecting the types of bearing used in the geartrain.

The second bearing 118 is shown positioned within the electricmotor-generator 106. However, other bearing arrangements with regard tothe electric motor-generator have been contemplated such as bearingarrangements with alternative quantities, types, and/or locations.

An output shaft 120 extending from the rotor shaft 114 of the electricmotor-generator 106 may be coupled to an input shaft 122. For instance,the output shaft 120 may be slip fit, mechanically attached, in splinedengagement, etc. with an end of the input shaft 122.

Bearings 125 are coupled to the input shaft 122. As such, the bearings125 support (e.g., axially and/or radially support) and facilitaterotation of the input shaft 122.

The electric drive axle assembly 102 include a gearbox 123 with a geartrain 124 with multiple gears. To elaborate, the gear train 124 may havea fixed ratio with multiple stages. It will therefore be understood thatthe gear train 124 is included in a multi-stage gear train assembly 127.A stage in the gear train is formed by two differently sized gearsdrivingly connected to and meshing with one another. Providing a fixedratio gear reduction decreases system complexity and increases systemreliability.

The gear train 124 includes a first gear 126 coupled to the input shaft122 and rotating therewith, a second gear 128 coupled to an intermediateshaft 130 and rotating therewith, and a third gear 132 coupled to theintermediate shaft 130 and rotating therewith. In the gear train 124,the first gear 126 meshes with the second gear 128. As described herein,a gear mesh is formed between mated gear teeth and enables power to betransferred between the meshed gears.

The third gear 132 meshes with a differential gear 134 (e.g., input ringgear) in a differential 104. The differential 104 is designed to allowfor axle shaft speed differentiation. Axle shafts 136 are rotationallycoupled to drive wheels 138, indicated by arrows 140.

The axle shafts 136 may form part of an axle 137. The axle 137 may be abeam axle, in one example. A beam axle, also referred to in the art as asolid axle or rigid axle, may be an axle with mechanical componentsstructurally supporting one another and extending between drive wheelscoupled to the axle. Thus, the camber angle between the wheels mayremain substantially unchanged as the axle moves through its travel. Forinstance, the beam axle may be a structurally continuous axle spanningthe drive wheels on a lateral axis, in one embodiment. In anotherembodiment, the beam axle may include co-axial shafts of thedifferential.

The differential 104 may include components such as a case housinggearing such as pinion gears, spider gears, etc. to achieve theaforementioned torque transfer functionality. To elaborate, thedifferential 104 may be an electronic locking differential, in oneexample. In another example, the differential 104 may be an electroniclimited slip differential or a torque vectoring dual clutch. In otherexamples, an open differential may be used. Referring to the lockingdifferential example, when unlocked, the locking differential may allowthe drive wheels 138 to spin at different speeds and conversely, whenlocked, the locking differential may force the drive wheels to rotate atthe same speed. In this way, the transmission configuration can beadapted to increase traction under certain driving conditions. In thecase of the limited slip differential, the differential allows thedeviation of the speed between shafts 136 coupled to the drive wheels138 to be constrained. Bearings 142 are coupled to the intermediateshaft 130 which support and facilitate rotation of the shaft. Bearings144 are coupled to the axle shafts 136.

The power path through the first electric drive axle may travel from themotor's output shaft 120 to the first gear 126, from the first gear tothe second gear 128, from the second gear to the third gear 132, fromthe third gear to the differential gear 134, and through thedifferential 104 and axle shafts 136 to the drive wheels 138.

The overall ratio of the gear train 124 may be less than or equal to10:1, in one example. In this way, the gear train may provide arelatively low gear ratio which may suite a variety of end-useapplications. Specifically, in one example, overall ratio of the geartrain may be between 10:1 and 5:1. This range may be particularlydesirable for motors with relatively lower operating speeds.

FIG. 1 schematically depicts a parking system 150 and a lubricationsystem 152. The parking system 150 may be designed to substantiallyprevent motion of the gear train via components such as an electronicand/or hydraulic actuator, a shift collar, a parking pawl, etc. used toaccomplish this functionality, indicated via arrow 154. The lubricationsystem 152 is configured to deliver lubricant (e.g., oil) to gearboxcomponents such as bearings 125, 142, and/or 144 as well as theinterface between the first gear 126 and the second gear 128 and theinterface between the third gear 132 and the differential gear 134.Arrows 156 indicate spray bars that may be used to lubricate the gears,although other types of components for routing lubricant to the gearssuch as splash lubrication devices may additionally or alternatively beutilized.

FIG. 2 shows a schematic depiction of a vehicle 200 having a secondexample of an electric drive axle 202 that again forms at least aportion of a vehicle drive train. The second example of the electricdrive axle assembly 202, shown in FIG. 2, and the first example of theelectric drive axle assembly 102 may be included in a vehicle productline 203. In the product line, common components may be retained betweenthe electric drive axle assemblies 102, 202 to reduce manufacturingcomplexity and cost. The shared components may include a housing (e.g.,housing 302, shown in FIGS. 3 and 6) that is profiled to accommodateboth the single and dual layshaft gear trains. The components which maybe shared between the electric drive axle assemblies in the product linemay further include bearings, parking devices, and/or the final drivegear reduction. Using these overlapping components allows multipleproduct arrangements to use several identical components, decreasingmanufacturing complexity across the product line.

Continuing with FIG. 2, the electric drive axle assembly 202 againincludes an electric motor-generator 204 with an output shaft 206coupled to an input shaft 207, an energy storage device 205, adifferential 208, axle shafts 213, and drive wheels 211. As indicatedabove, these components may share a similar form and/or function withthe associated components described with regard to FIG. 1. Redundantdescription of these components is omitted for concision.

The electric drive axle 202 further includes a gearbox 209 with a geartrain 210. The gear train 210 in the second example of the electricdrive axle assembly 202 includes multiple intermediate shafts (a firstintermediate shaft 212 and a second intermediate shaft 214) and theinput shaft 207. It be understood that the gear train 210 is included ina multi-stage gear train assembly 217. The input shaft 207 againincludes a first gear 216. It will be understood, that the first gear216 may be sized differently from the first gear 126, depicted in FIG.1.

Continuing with FIG. 2, the first intermediate shaft 212 includes asecond gear 218 that meshes with the first gear 216 and a third gear 220that meshes with a fourth gear 222 on the second intermediate shaft 214.A fifth gear 224 resides on and is rotationally coupled to the secondintermediate shaft 214, in the illustrated example. Further, as shown inFIG. 2, the fifth gear 224 is coupled to a differential gear 226.

In a drive mode, the power path through the gear train 210 starts at themotor-generator 204, travels from the first gear 216 to the second gear218 on the first intermediate shaft 212, from the second gear to thethird gear 220 by way of the first intermediate shaft, from the thirdgear to the fourth gear 222. The power path continues through the secondintermediate shaft 214 to the fifth gear 224, from the fifth gear to thedifferential gear 226, and to the axle shafts and subsequently the drivewheels 211 by way of the differential.

The overall ratio of the gear train 210 may be greater than 10:1, in oneexample. In this way, the gear train may provide a relatively high gearratio which may suite a variety of end-use applications. Specifically,in one example, overall ratio of the gear train may be between 11:1 and20:1. This range may be particularly desirable for motors withrelatively higher operating speeds.

An axis system 180 is also provided in FIG. 1 as well as FIGS. 2-9, forreference. In one example, the z-axis may be parallel to a vertical axis(e.g., gravitational axis), the x-axis may be a lateral axis, and they-axis may be a longitudinal axis. However, other orientations of theaxes may be used, in other examples.

FIG. 2 again schematically depicts a parking system 250 and alubrication system 252. The parking system 250, shown in FIG. 2, may besimilar to the parking system 150, shown in FIG. 1. Likewise, thelubrication system 252, shown in FIG. 2, may be similar to thelubrication system 152, shown in FIG. 1. To elaborate, spray bars 254may be similar to spray bars 156, shown in FIG. 1. The allocation ofsimilar components across the product line gearboxes allowsmanufacturing efficiency to be increased, which may in turn decreasemanufacturing costs.

Further in some examples, the differential 208 may have a final driveratio that is equivalent to a final drive ratio of the differential 104,shown in FIG. 1. The final drive ratio may be selected based on themotor's speed range, efficiency curves, vehicle performance targets,etc. For instance, the final drive ratio may be between 2:1 and 6:1,however numerous suitable ranges are possible. Again, manufacturingefficiency gains may further increased when the gearboxes in the productline share common components.

FIG. 3 shows a perspective view of an example 300 of the second electricdrive axle, shown in FIG. 2. The second electric drive axle 300 mayinclude a housing 302, a gearbox 304 with a gear train 305, and adifferential 306. It will be appreciated that the gear train 305 may beincluded in a multi-stage gear train assembly 307.

The housing 302 may have a clamshell construction which encloses thegear train 305, the differential 306, and a motor schematically depictedat 310. Access panels, schematically depicted at 312, may provideefficient access to the gearbox 308, differential 306, and/or the motor310, in the clamshell construction embodiment. The access sections 312(e.g., access panels) may be mechanically attached (e.g., attached viabolts, screws, clamps, etc.,) or otherwise removably coupled to flanges313 in a central section 315 of the housing 302. The housing 302specifically includes an interior enclosure 314 that at least partiallysurrounds the differential and an interior enclosure 316 that at leastpartially surrounds the gear train 305. Axle shaft openings 318 may befurther included in the housing 302. The axle shaft openings may becylindrical in profile and extend away from the differential gear 322.The housing 302 may further include a differential protrusion 320 thatextends in opposing directions along the z-axis to enable thedifferential gear 322 to be efficiently packaged in the housing.Additionally, the housing 302 may include a cylindrical section 324 thatis profiled to house the motor-generator.

The gear train 305 includes an input shaft 326 rotationally coupled toan output shaft of an electric motor-generator. The input shaft 326 isrotationally coupled to a first intermediate shaft 328 via a first gear329 and second gear 330, shown in FIG. 5. Continuing with FIG. 3, thefirst intermediate shaft 328 may be rotationally coupled to a secondintermediate shaft 332 which is rotationally coupled to the differentialgear 322.

FIG. 3 further illustrates a third gear 333 on the first intermediateshaft 328 meshing with a fourth gear 334 on the second intermediateshaft 332. As previously discussed, a fifth gear on the secondintermediate shaft meshes with the differential gear 322.

Bearings 335, 336, 338 are coupled to the input shaft 326, firstintermediate shaft 328, and the second intermediate shaft 332. Thebearings 335 are depicted as ball bearings and the bearings 336, 338 aredepicted as roller bearings, although the types of bearings deployed inthe gear train may be varied based on expected gear speed ranges, gearsizes, expected gear and shaft loading, etc.

A case 340 of the differential 306 is further illustrated and may holdspider gears that drive side gears that are rotationally attached toaxle shafts. However, alternate types of differential arrangements liewithin the scope of this disclosure.

FIG. 4 shows a side view of the electric drive axle 300 with themulti-stage gear train assembly 307, shown in FIG. 3. The housing 302and the gearbox 304 with the gear train 305 are again illustrated alongwith the input shaft 326, the first intermediate shaft 328, the secondintermediate shaft 332, gears 329, 330, 333, 334, bearings 335, 336, 338and differential gear 322 of the differential 306.

Rotational axes 400, 402, 404, 406 of the input shaft 326, the firstintermediate shaft 328, and the second intermediate shaft 332, and thedifferential 306, respectively, are depicted. These rotational axes mayeach have varying vertical positions along the z-axis to enable thegears in the gear train assembly 307 to be efficiently packaged in theinterior enclosure 316 of the housing 302. Specifically, in one example,the rotational axes 402, 404 of the first and second intermediate shafts328, 332, respectively, may be positioned vertically above therotational axis 406 of the differential 306 and the rotational axis 400of the input shaft 326 may be positioned vertically below thedifferential's rotational axis. Arranging the axes in this manner mayenable the gear train to achieve a desired gear ratio while maintainingan acceptable level of packaging efficiency. However, the axes may haveother relative positions, in other examples. The differential'srotational axis 406 may further be axially offset from the outputshaft's rotational axis 400 to further increase packaging efficiency andconcentrate a greater amount of mass near the center of the vehiclewhich may enhance vehicle handling performance.

The housing 302 includes an upper side 410, a lower side 412, andlateral sides 414, 416. The lateral side 414 may include a curvedsection 418 that is contoured to accommodate for packaging of the firstintermediate shaft 328 and the gears that reside thereon. The radius ofthe curvature of section 418 may be similar to the radius of curvatureof the gear 330. In this way, the housing may efficiently package thegearing. However, other housing profiles lie within the scope of thisdisclosure.

Turning to FIG. 5, it shows the multi-stage gear train assembly 307 withthe housing removed to reveal the internal gear stages. The input shaft326, the first intermediate shaft 328, the second intermediate shaft332, and the differential 306 are again shown along with gears 329, 330,333, 334 and bearings 335, 336, 338 are again illustrated.

A center distance between the input shaft 326 and the secondintermediate shaft 332 is indicated at 500. This center distance may beselected (e.g., optimized) so that for the single intermediate shaftaxle assembly, shown in FIG. 6, the size of the gear 329 and the gear333, shown in FIGS. 3 and 4, may only need to be changed to achieve avariation in gear ratio between the gear trains.

FIG. 5 further shows a center distance 502 between the input shaft 326and the second intermediate shaft 332, a center distance 502 between andthe differential 306 and the input shaft, and a center distance 504between the differential and the second intermediate shaft 332. A centerdistance 506 between the first intermediate shaft 328 and the inputshaft 326 as well as a center distance 508 between the firstintermediate shaft 328 and the second intermediate shaft 332 is furtherillustrated.

FIG. 5 additionally includes a fifth gear 510 meshing with thedifferential gear 322. A differential bearing 512 allowing for rotationof an axle shaft passing through the case 340. It will be appreciatedthat the differential gear 322 drives rotation of the case which rotatesspider gears meshing with side gears that are rotationally coupled toaxle shafts.

FIG. 6 shows an example 600 of the first electric drive axle with afirst multi-stage gear train assembly 602, shown in FIG. 1. The firstmulti-stage gear train assembly 602 may include a housing 302, a gearbox606 with a gear train 608, and a differential 610, similar to the secondgear train assembly.

As shown in FIG. 6 the gear train 608 includes an input shaft 612 andone intermediate shaft 614, differing from the second gear trainassembly, shown in FIGS. 3-5. The housing 302, shown in FIG. 6, however,is identical in profile and sizing to the housing 302 shown in FIGS.3-4. In this way, a common housing is used across different assembliesin the vehicle product line. This enables manufacturing of the differentassemblies in the product line to be simplified and costs to be reduced,if desired. Bearings 616, and 618 may again be coupled to the inputshaft 612 and the intermediate shaft 614 and may be identical to thebearings 335, 337, shown in FIGS. 3-5. In this way the product line'smanufacturing process may be further simplified.

Rotational axes 620, 622, 638 of the input shaft 612, the intermediateshaft 614, and the differential 610 are additionally depicted. The axes620 and 638 may be similarly positioned in relation to the axes 400, 406shown in FIG. 4, allowing these gear train assemblies to have additionaloverlapping features.

The housing 302 includes an interior enclosure 607 with a section 609devoid of gears or shafts, which in the other gear train assembly, shownin FIGS. 3-5, houses an intermediate shaft and corresponding gears. Thesection 609 of the interior enclosure 607 extends away from thedifferential in a direction parallel to the y-axis. The section 609 maybe bounded via two sidewalls 630 that join at a bend 632 in the wall ofthe housing.

An input gear 634 and an output gear 636, shown in FIG. 7, resides onthe intermediate shaft 614. As previously discussed, the input gear 634on the intermediate shaft meshes with a gear on the input shaft 612. Thedifferential gear 640 designed to rotate about axis 638 is furtherillustrated. Housing sections, schematically illustrated at 642, mayattach to flanges 644 to enclose the stages in the gearbox. Adifferential bearing 646 is additional shown in FIG. 6, with similarfunctionality and structure to the previously described differentialbearing.

FIG. 7 illustrates the first multi-stage gear train assembly 602 withthe housing removed to reveal the internal gear stages. The input shaft612, the intermediate shaft 614, and the differential 610 are againshown along with gears 634, 636 and bearings 616, 618, 646 are againillustrated.

A center distance 700 between the differential 610 and the intermediateshaft 614, a center distance 702 between the differential 610 and theinput shaft 612, and a center distance 704 between the input shaft 612and the intermediate shaft 614 are depicted in FIG. 7.

FIGS. 8 and 9 shows the first intermediate shafts 332 and 614,respectively. The gears 334, 510 are shown arranged on the intermediateshaft 332 and the gears 634, 636 are shown arranged on the intermediateshaft 614. Bearings 338, 618 are further shown coupled to shafts 332 and614, respectfully.

As shown, the gear 634 has a greater diameter 900 than the diameter 800of the gear 334 to facilitate an efficient ratio swap between thedifferent gear train assemblies in the product line. The gears 634, 334may be press fit to the corresponding shaft, to enable an efficient gearstage ratio adjustment.

FIGS. 1-9 show example configurations with relative positioning of thevarious components. If shown directly contacting each other, or directlycoupled, then such elements may be referred to as directly contacting ordirectly coupled, respectively, at least in one example. Similarly,elements shown contiguous or adjacent to one another may be contiguousor adjacent to each other, respectively, at least in one example. As anexample, components laying in face-sharing contact with each other maybe referred to as in face-sharing contact. As another example, elementspositioned apart from each other with only a space there-between and noother components may be referred to as such, in at least one example. Asyet another example, elements shown above/below one another, at oppositesides to one another, or to the left/right of one another may bereferred to as such, relative to one another. Further, as shown in thefigures, a topmost element or point of element may be referred to as a“top” of the component and a bottommost element or point of the elementmay be referred to as a “bottom” of the component, in at least oneexample. As used herein, top/bottom, upper/lower, above/below, may berelative to a vertical axis of the figures and used to describepositioning of elements of the figures relative to one another. As such,elements shown above other elements are positioned vertically above theother elements, in one example. As yet another example, shapes of theelements depicted within the figures may be referred to as having thoseshapes (e.g., such as being circular, straight, planar, curved, rounded,chamfered, angled, or the like). Additionally, elements co-axial withone another may be referred to as such, in one example. Further,elements shown intersecting one another may be referred to asintersecting elements or intersecting one another, in at least oneexample. Further still, an element shown within another element or shownoutside of another element may be referred as such, in one example. Inother examples, elements offset from one another may be referred to assuch.

The invention will be further described in the following paragraphs. Inone aspect, a vehicle product line is provided that comprises a firstmulti-stage gear train assembly including at least two stages; a secondmulti-stage gear train assembly including at least three stages and adifferent number of stages than the first multi-stage gear trainassembly; and a housing including a first section removably attached toa second section; wherein the second section is configured to receivethe first and second multi-stage gear train assemblies in differentproduct arrangements.

In another aspect, a vehicle product line is provided that comprises afirst multi-stage gear train assembly with a fixed gear ratio andincluding: one intermediate shaft with a gear coupled thereto andconfigured to form a mesh with a gear on a first input shaft and a gearin a first differential; a second multi-stage gear train assembly with afixed gear ratio and including: a first intermediate shaft with a gearcoupled thereto and configured to form a mesh with a gear on a secondinput shaft; and a second intermediate shaft with a gear coupled theretoand configured to form a mesh with a gear in a second differential; anda housing including a first section removably attached to a secondsection; wherein the second section is configured to receive the firstmulti-stage gear train assembly in a first solid beam axle arrangementand the second multi-stage gear train assembly in a second solid beamaxle arrangement.

In any of the aspects or combinations of the aspects, the first andsecond multi-stage gear train assemblies may include a firstdifferential and a second differential, respectively, that may be eachdesigned to rotationally couple to a pair of axle shafts.

In any of the aspects or combinations of the aspects, an overall gearratio of the first multi-stage gear train assembly may be less than anoverall gear ratio of the second multi-stage gear train assembly.

In any of the aspects or combinations of the aspects, the vehicleproduct line may further comprise an electric motor-generator designedto rotationally couple to the first and second multi-stage gear trainassemblies, wherein the electric motor-generator, when separatelyassembled with each of the first and second multi-stage gear trainassemblies, is axially offset from the first differential and the seconddifferential.

In any of the aspects or combinations of the aspects, an overall gearratio of the first multi-stage gear train assembly may be greater than10:1 and an overall gear ratio of the second multi-stage gear trainassembly may be less than 10:1.

In any of the aspects or combinations of the aspects, when assembled inthe housing, the first multi-stage gear train assembly and the secondmulti-stage gear train assembly may each form a beam axle.

In any of the aspects or combinations of the aspects, the firstmulti-stage gear train assembly and the second multi-stage gear trainassembly may have an equivalent final drive ratio.

In any of the aspects or combinations of the aspects, the first andsecond multi-stage gear train assemblies may each include a parkingsystem designed to prevent rotation of the corresponding multi-stagegear train assembly.

In any of the aspects or combinations of the aspects, the firstmulti-stage gear train assembly may include a first lubrication systemwith a first set of spray bars and the second multi-stage gear trainassembly may include a second lubrication system with a second set ofspray bars.

In any of the aspects or combinations of the aspects, the firstmulti-stage gear train assembly may include a single intermediate shaftand the second multi-stage gear train assembly includes two intermediateshafts.

In any of the aspects or combinations of the aspects, the product line,which may be a vehicle line, a transmission line, an axle line, etc.,may further comprise an electric motor-Page generator configured torotationally couple to the first and second multi-stage gear trainassemblies and wherein the housing is configured to enclose the electricmotor-generator.

In any of the aspects or combinations of the aspects, the firstdifferential may be axially offset from the electric motor-generator inthe first solid beam axle arrangement and the second differential may beaxially offset from the electric motor-generator in the second solidbeam axle arrangement.

In any of the aspects or combinations of the aspects, the firstmulti-stage gear train assembly may have an overall gear ratio between5:1 and 10:1 and the second multi-stage gear train assembly may have anoverall gear ratio between 11:1 and 20:1.

In any of the aspects or combinations of the aspects, the first andsecond multi-stage gear train assemblies may each include a parkingsystem that are substantially identical to one another.

In any of the aspects or combinations of the aspects, a final driveratio of the first differential and the second differential may beequivalent.

In any of the aspects or combinations of the aspects, the firstmulti-stage gear train assembly may include a first set of bearingscoupled to the one intermediate shaft and the second multi-stage geartrain assembly may include a second set of bearings coupled to the firstintermediate shaft and similar to the first set of bearings.

In any of the aspects or combinations of the aspects, when the first andsecond multi-stage gear train assemblies are separately installed in thehousing, the first input shaft and the second input shaft may have acommon rotational axis and the first and second differentials have acommon rotational axis.

In any of the aspects or combinations of the aspects, the housing mayinclude a flange circumferentially surrounding the first multi-stagegear train assembly in the first solid beam axle arrangement and thesecond multi-stage gear train assembly in the second solid beam axlearrangement.

In any of the aspects or combinations of the aspects, when the first andsecond multi-stage gear train assemblies are separately installed in thehousing, the housing may circumferentially enclose each of the gears inthe respective multi-stage gear train assembly.

In another representation, an electric axle product line is providedwith a clamshell housing profiled to enclose a first gear reduction witha single idler shaft and a second gear reduction with multiple idlershafts that when assembled form separate gear reduction products.

As used herein, the term “approximately” is construed to mean plus orminus five percent of the range unless otherwise specified.

While various embodiments have been described above, it should beunderstood that they have been presented by way of example, and notlimitation. It will be apparent to persons skilled in the relevant artsthat the disclosed subject matter may be embodied in other specificforms without departing from the spirit of the subject matter. Theembodiments described above are therefore to be considered in allrespects as illustrative, not restrictive.

It will be appreciated that the configurations disclosed herein areexemplary in nature, and that these specific examples are not to beconsidered in a limiting sense, because numerous variations arepossible. For example, the above technology can be applied topowertrains that include different types of propulsion sources includingdifferent types of electric machines and transmissions. The subjectmatter of the present disclosure includes all novel and non-obviouscombinations and sub-combinations of the various systems andconfigurations, and other features, functions, and/or propertiesdisclosed herein.

The following claims particularly point out certain combinations andsub-combinations regarded as novel and non-obvious. These claims mayrefer to “an” element or “a first” element or the equivalent thereof.Such claims should be understood to include incorporation of one or moresuch elements, neither requiring nor excluding two or more suchelements. Other combinations and sub-combinations of the disclosedfeatures, functions, elements, and/or properties may be claimed throughamendment of the present claims or through presentation of new claims inthis or a related application. Such claims, whether broader, narrower,equal, or different in scope to the original claims, also are regardedas included within the subject matter of the present disclosure.

1. A product line, comprising: a first multi-stage gear train assemblyincluding at least two stages; a second multi-stage gear train assemblyincluding at least three stages and a different number of stages thanthe first multi-stage gear train assembly; and a housing including afirst section removably attached to a second section; wherein the secondsection is configured to receive the first and second multi-stage geartrain assemblies in different products of the product line.
 2. Theproduct line of claim 1, wherein the first and second multi-stage geartrain assemblies include a first differential and a second differential,respectively, that are each designed to rotationally couple to a pair ofaxle shafts.
 3. The product line of claim 2, wherein an overall gearratio of the first multi-stage gear train assembly is less than anoverall gear ratio of the second multi-stage gear train assembly.
 4. Theproduct line of claim 2, further comprising an electric motor-generatordesigned to rotationally couple to the first and second multi-stage geartrain assemblies, wherein the electric motor-generator, when separatelyassembled with each of the first and second multi-stage gear trainassemblies, is axially offset from the first differential and the seconddifferential.
 5. The product line of claim 1, wherein an overall gearratio of the first multi-stage gear train assembly is greater than 10:1and an overall gear ratio of the second multi-stage gear train assemblyis less than 10:1.
 6. The product line of claim 1, wherein, whenassembled in the housing, the first multi-stage gear train assembly andthe second multi-stage gear train assembly each form a beam axle.
 7. Theproduct line of claim 1, wherein the first multi-stage gear trainassembly and the second multi-stage gear train assembly have anequivalent final drive ratio.
 8. The product line of claim 1, whereinthe first and second multi-stage gear train assemblies each include aparking system designed to prevent rotation of the correspondingmulti-stage gear train assembly.
 9. The product line of claim 1, whereinthe first multi-stage gear train assembly includes a first lubricationsystem with a first set of spray bars and the second multi-stage geartrain assembly includes a second lubrication system with a second set ofspray bars.
 10. The product line of claim 1, wherein the firstmulti-stage gear train assembly includes a single intermediate shaft andthe second multi-stage gear train assembly includes two intermediateshafts.
 11. A product line, comprising: a first multi-stage gear trainassembly with a fixed gear ratio and including: one intermediate shaftwith a gear coupled thereto and configured to form a mesh with a gear ona first input shaft and a gear in a first differential; a secondmulti-stage gear train assembly with a fixed gear ratio and including: afirst intermediate shaft with a gear coupled thereto and configured toform a mesh with a gear on a second input shaft; and a secondintermediate shaft with a gear coupled thereto and configured to form amesh with a gear in a second differential; and a housing including afirst section removably attached to a second section; wherein the secondsection is configured to receive the first multi-stage gear trainassembly in a first solid beam axle arrangement and the secondmulti-stage gear train assembly in a second solid beam axle arrangement.12. The product line of claim 11, further comprising an electricmotor-generator configured to rotationally couple to the first andsecond multi-stage gear train assemblies and wherein the housing isconfigured to enclose the electric motor-generator.
 13. The product lineof claim 12, wherein the first differential is axially offset from theelectric motor-generator in the first solid beam axle arrangement andthe second differential is axially offset from the electricmotor-generator in the second solid beam axle arrangement.
 14. Theproduct line of claim 11, wherein the first multi-stage gear trainassembly has an overall gear ratio between 5:1 and 10:1 and the secondmulti-stage gear train assembly has an overall gear ratio between 11:1and 20:1.
 15. The product line of claim 11, wherein the first and secondmulti-stage gear train assemblies each include a parking system that aresubstantially identical to one another.
 16. The product line of claim15, wherein a final drive ratio of the first differential and the seconddifferential are equivalent.
 17. The product line of claim 11, whereinthe first multi-stage gear train assembly includes a first set ofbearings coupled to the one intermediate shaft and wherein the secondmulti-stage gear train assembly includes a second set of bearingscoupled to the first intermediate shaft and similar to the first set ofbearings.
 18. The product line of claim 11, wherein, when the first andsecond multi-stage gear train assemblies are separately installed in thehousing, the first input shaft and the second input shaft have a commonrotational axis and the first and second differentials have a commonrotational axis.
 19. The product line of claim 18, wherein the housingincludes a flange circumferentially surrounding the first multi-stagegear train assembly in the first solid beam axle arrangement and thesecond multi-stage gear train assembly in the second solid beam axlearrangement.
 20. The product line of claim 11, wherein, when the firstand second multi-stage gear train assemblies are separately installed inthe housing, the housing circumferentially encloses each of the gears inthe respective multi-stage gear train assembly.